Bass reflex loudspeaker systems are frequently used in sound engineering. In bass reflex loudspeaker systems, the loudspeaker housing is not closed, but rather provided with a channel leading to the outside. The term ventilated or vented systems is also used. The sound component radiated backwards from the loudspeaker is used in order to increase the efficiency of the loudspeaker system in the region of the resonant frequency of the loudspeaker system. It is possible to achieve significantly increased sound pressure levels and an extension of the power bandwidth.